Ok...this is not my normal way of cooking, but the recipe seems to produce my favorite pot roast. Apologies if you aren't into mixes and packets of seasonings. Here goes:

For a 3-4lb chuck roast: place roast in slow cooker. Mix together 1 packet of Italian salad dressing mix, 1 packet of ranch dressing mix, and 1 packet of brown gravy mix. Sprinkle the dry mixture over the roast. Pour 1/2 cup of water around the roast. Cook on low for about 6-8 hours. I would start checking for doneness at around 5 hours since slow cookers can vary alot and an overdone pot roast is inedible. This makes very good gravy that I like to pour over mashed potatoes or noodles.